// pages/calc/calc.js
Page({

  /**
   * 页面的初始数据
   */
  data: {
    num: '0',
    op: ''
  },
result: null,
isClear:false,
numBtn:function(e){
   var num = e.target.dataset.val
   if(this.data.num==='0' || this.isClear){
     this.setData({num:num})
     this.isClear = false
   }else{
     this.setData({num:this.data.num+num})
   }
},
opBtn:function(e){
  var op = this.data.op
  var num = Number(this.data.num)
  this.setData({op:e.target.dataset.val})
  if(this.isClear){
    return
  }
  this.isClear = true
  if(this.result===null){
    this.result = num
    return
  }
  if(op==='+'){
    this.result = this.result + num
  }else if(op==='-'){
    this.result = this.result - num
  }
  else if(op==='*'){
    this.result = this.result * num
  }else if(op==='/'){
    this.result = this.result / num
  }else if(op==='%'){
    this.result = this.result % num
  }
  this.setData({num: this.result+''})
},
dotBtn:function(){
  if(this.isClear){
    this.setData({num: '0.'})
    this.isClear=false
    return
  }
  if(this.data.num.indexof('.')>=0){
    return
  }
  this.setData({num: this.data.num+'.'})
},
delBtn:function(){
  var num=this.data.num.substr(0,this.data.num.length -1)
  this.setData({num: num===''?'0':num})
},
resetBtn:function(){
  this.result=null
  this.isClear=false
  this.setData({ num:'0',op:''})
}
 
})